At present, the commonly used aluminum alloy cylinder head materials at home and abroad are mainly Al-Si series alloys. The common material choices are ZL101A (A356, G-AlSi7Mg), ZL104 (AC4B), ZL106 (328.0 US), ZL107, and A-S5U3 (France) alloys. In addition, ZL111 (A354) alloy is used as one of the engine cylinder head materials by adding Cu and Mg strengthening elements to the traditional Al-Si alloy and obtaining higher strength after heat treatment.
| Si | Cu | Mg | Mn | Ti | Al | Impurity Fe |
| 6~8 | 1.3~1.8 | 0.3~0.5 | 0.1~0.3 | 0.1~0.25 | Allowance | ≤0.35 |
The cylinder head of diesel engine for combat vehicles requires not only higher thermal strength, but also good plasticity. Chen Jisen et al. carried out composition optimization on the basis of cylinder head material ZL111, reduced the content of Si to 6%~8%, adjusted the content of Cu to 1.3%~1.8%, controlled the content of Mg to 0.3%~0.5%, added Ti, B, Zr elements to refine the grain, and used Sr elements to carry out Si modification, and finally obtained a new cast aluminum alloy ZL702A with high heat resistance and good strength and toughness. The service life of ZL702A cylinder head is significantly longer than that of ZL101 alloy cylinder head when it is applied to the cylinder head of high-power diesel engine. Therefore, ZL702A alloy is selected as the cylinder head material of diesel engine in this paper. The composition of ZL702A alloy is shown in Table 1, and the performance comparison with other cylinder head materials is shown in Table 2.
| Serial number | Alloy grade | Rm (normal temperature)/MPa | Rp0.2/MPa | A/% | Heat treatment status | Casting method |
| 1 | ZL101A、A356、 G-AlSi7Mg | 275 | 185 | 5.0 | T6 | Metal mold casting |
| 2 | ZL106、328.0 | 265 | 160 | 2.0 | T6 | Metal mold casting |
| 3 | ZL104、 AC4B | 255 | 195 | 4.0 | T6 | Metal mold casting |
| 4 | ZL107 | 275 | 185 | 3.0 | T6 | Metal mold casting |
| 5 | ZL111、A354 | 380 | 285 | 6.0 | T6 | Metal mold casting |
| 6 | ZL702A | 372 | — | 8.0 | T6 | Metal mold casting |